PRESSURE TESTING OF ANNULAR AND PIPE RAM BOPs (Fig. Open blind rams with 105.6 kg/cm2 (1500 psi). Check all the valves, flanges apd seals that are under pressure for leaks and tighten if necessary. If pressure is holding, increase the pressure upto final test pressure as decided and hold for 5 minutes. Apply pressure by cementing unit or test pump through main kill line and pressurize upto 15 to 25 kg/cm2 and hold for 3 minutes. Check closing line and preventer for leaks. Close blind rams with 105.6 kg/cm2 (1500 psi) closing pressure. Fill and top up BOP stack bore with water. Close valve no.7& 9 on choke line and 2 & 3 on kill line. Open both the valves on casing head below test plug seals to recognize leaking seal and prevent formation or casing damage in case of any leakage through test plug. Open all the valves and chokes on choke manifold and allow water to flow through each outlet. If the test plug is of open bore type, make sure that it is run-in with bull plug to isolate casing and open hole from test pressures. Note: Ensure that test plug size, shape and contour matches with that of casing head where it will seat. Make up appropriate casing head test plug on top of a stand of drill collar and run-in the same on a joint of drill pipe. PRESSURE TESTING OF BLIND RAMS (Fig.15.1) 1. Reference: Drilling Operational Manual/ Institute of Drilling Technology/ONGC/Chapter-15 TEST PROCEDURE Detailed step wise procedure for pressure testing of BOP stack and other associated equipment is as under An exception is the annular preventer which should be tested to 50% of its rated pressure to minimize packoff element wear or damage. However, in no case the test pressure should be less than the expected surface pressure. On subsequent tests as mentioned above, the BOP stack should be tested to at least 70% of the preventer rated working pressure but limited to the least of the rated working pressure of the wellhead and 90%of the burst pressure of the upper part of casing string. (2) Rated working pressure of the well head. High pressure test Once the equipment clears the low pressure test, it should be tested to a pressure to be decided as explained below: On installation of the BOP stack, the test pressure should be minimum of the following: (1) Rated working pressure of the preventer stack. Low pressure test A low test pressure in the range of 15-25 kg/cm2 (200 to 350 psi) should be carried out. TEST PRESSURE Both low pressure and high pressure testing procedure should be followed. (5) following repairs that require breaking a pressure connection. (3) prior to entry into a transition zone. TEST FREQUENCY BOP stack should be pressure tested (1) when installed. PRESSURE TESTING OF BOPs & CHOKE MANIFOLD TEST FLUID Clean water should be used as test fluid.
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